Metering system for telephony



May 13, 1952 E. UNGAR METERING SYSTEM FOR TELEPHONY Filed April l5. 194947.1.... wu.. 4.\ \W 0/ w M 5...... f1 .,1 m/ W V Q..." H.. .a/W M .MWav .l :Il wf/IIIIVI HIL/m INVENTOR Patented May 13, 1952 METERINGSYSTEM Foa TELEPHONY Ernest ngar, Copenhagen, Denmark, assignor ofone-half to Telefon Fabrik Automatic A/S, Copenhagen, Denmark, ajoint-stock company of Denmark Application April 15, 1949, Serial No.87,751 In Denmark April 21, 1948 3 Claims. (Cl. 179-7.1)

The charge to be -made for trunk calls in a telephone system isordinarily computed from a tariii based on a conversational period ofthree minutes as a unit.

In automatic systems, the charge for trunk calls is ordinarily madewholly or in part on the subscribers meter by means of pulse series thatare transmitted at the commencement of each conversational period.Accordingly, when calling from a coin operated telephone, the callingparty must pay the `total amount for the Whole of the conversationalperiod before a call can be estabn lished.

It would be a considerable advantage if it were possible to have a callestablished for a shorter period than the said three minutes, if theperson wanting the call does not for the moment dispose .of coinscorresponding to a three minutes call.

i Moreover, it might be contemplated to adopt a fcharging systemaccording to which the charge jicr calls was not based on periods of apredeter mined length, but on the actual duration of the ,conversationviz. by means of pulses transmitted 1 to the subscribers meter atregular intervals dis -itributed over the duration of the conversation..Ii so, the time interval between the metering pulses must vary with thedistance of the desired ,substation from the calling subscriber, i. e.in the lcase of calls over shorter distances, Where the :unit charge isdifferent from that applying to y'calls over longer distances, thepulses must be itransmitted at greater time intervals than in the caseof calls over longer distances.

:The present invention relates to an arrange- .ment in metering circuitsin which such a change of the existing charging systems is renderedpossible Without necessitating a replacement of the time zone meteringdevices of existing automatic telephone systems. By the invention, it isalso made possible under the existing charging system with aconversational period of a predetermined length, to make a trunk callfrom a coin operated telephone by means of metering pulses over part ofthe period only against payment of a corresponding fraction of thecharge. To obtain this, the invention is characterized in that betweenthe source delivering the metering pulses, and the metering circuit or acoin control circuit, if such a circuit is provided, a device isinterposed that receives the metering pulses and extends such pulses orsome of them to the metering circuit or the coin control circuit or bothat a time interval which is longer than the time interval between thepulses delivered by the said source and depends on the number ofmetering pulses received at the `commencement of the period, the saiddevice comprising a member adapted to be automatically set under theinfluence of the metering pulses received and a member adapted under theiniiuence of other pulses transmitted at predetermined time intervals tobe advanced step by step and being connected With the rst named memberin such a manner that Whenever advanced by a number of steps dependingon the position of said first named member it will transmit a settingpulse to the metering circuit and at the same time to a member which isconstructed in such a manner as to be advanced by one step upon receiptof each pulse and is so connected with the member set by the meteringpulses received that when advanced to a position corresponding to thatof the last named member, said mem-ber causes a circuit to be closedwhich causes the transmission of pulses to the metering circuit or coincontrol circuit or both to be stopped.

The invention will best be understood from the following explanation ofthe functionof the circuit shown by way of an example in theaccompanying drawing which circuit is so constructed that within aconversational period a numberl of pulses corresponding to the chargefor the call in question are transmitted at regular intervals uniformlydistributed over the period to themetering device, counting mechanismor/and the coin control circuit of a coin control station, so that thenumber of the pulses corresponds to the number of pulses received from acharging device at the commencement of the period.

When the central station C to which a calling subscriber A1 and a calledsubscriber A2 are connected in the ordinary manner by way of coneductors L1 and L2 respectively, at the commencement of a conversationperiod transmits metering pulses by Way of a source M1, these pulses areby way of a conductor Dfi received by a relay ST. When the iirst one ofthese pulses operated the relay ST, the latter closes temporarily anumber of contacts sti, sti, sta. The contact stl energizes a relay SO,which works with a certain. delay so as to remain attracted during thewhole of the period between each two consecutive metering pulsestransmitted to the relay ST from outside. At the same time, the relay STenergizes the switching magnet TAVK of a step by step switch TAV by wayof the contact stz. The switch TAV is thereby advanced by one step. Thisis repeated every time a metering pulse is received by the relay ST.

The relay SO when operated changes over a number of contacts soi, soz,sos. The contact sos closes a circuit from a conductor Bi by wayof abreaking contact ssz, the contact soa and the control coil of a relaySK, whereby this relay op- The iirst pulse, or inthe embodimentdescribed,

the rst and the second pulse received by the relay ST is extended overthe conductor Die di'- rectly to a metering circuit, not shown, Vwhichmay be of well known design and does not form part of the invention. Thesaid metering circuit is connected to the conductors Dfo and Bl The saidextension of the pulses lis effected by the contact sta whichsynchronously with the operation of the relay ST closes a circuitconnection from earth by way of the bank contacts 'and i of the banklevel TAVJ), which contacts are connected to the conductor Dfowhen thesaid switch TAVis advanced through the iirst and the second of these twocontact positions which is er- Vfected by the contact stz controlled bythe relay 'VST energizing the switching magnet'TVAK of the switch TVA.

When the relay ST receives the third-on` if Vthe terminal I of thebankTAV-b is not connected to`the conductor 'Dio-then the second meteringpulse and ,thereby-causes the switching magnet TAVK; to advancethesWitchTAV to its next contact position i inthe embodiment shown thethird contact position, the connection from vthe contact sta to theconductor Dfo in thejbank level TAV-b is interrupted. vThisthirdmetering pulse and the subsequentmetering*pulse received via therelayVST are therefore no1-transferred tothe metering circuit but justadvance the Vswitch TAV by one step in response toeach pulse received. nY Y,

n When 'the relay ST does no longer receive pulses, e. g. when the wiperlw of the'various switch levels VTAV--a,--TAV-,d have been set, e. g. inthe position w1 shown in dotted lines, the relay SO isder-energizedbecause the contact sti remains opened. A contact sollcontrolled by the relay SO is thereby closed which has the ,effect thatthe switching magnet TCVK of a switch TCV automatically receives specialcurrent pulses, so-

calledtiming pulses, i. e. pulses that are automatically transmitted atconstant time intervals Vwiper tw and the contact 25 ofthe bank levelTCV-d and a breaking contact syz to the switching magnet TBVK and thenceviavthe current source E to earth. Thus operated, the v'switch TBV movesto position i. The bank contacts of n the various levels ofthe switchTCV are, as shown, connectedwith the bank contacts of the level c of theswitch 'rAv-in such a vmanner that during the rotary movement of theswitch TCV, some of the timing pulses are extended by way oi the banklevels of this switch and the contacts of the bank level TAV-c to arelay SEC, so that, as will be described below, this relay during aconversational period receives a number ci the said timing pulsesuniformly distributed over the conversational period, viz. a numberamounting to one pulse less than the number of metering pulses remceived via tho relay ST.

Upon receipt ci each timing pulse, the relay SEC operates and closes acontact sieg. As will be described below, Athe iirst timing pulsereceived by the relay SIC will'not release any pulse to the metering'circuit, not shown, connected to the conductors Dio and'Bi, because acontact S31,

which is=controlled by a relay SL and is connected in series with thecontact sz'cz, keeps vthe connection between the metering circuit andVthe conductor Dio interrupted. The rst timing pulse only'has the eiiectthat a relay SM is energized by way of three contacts ssi, sica 'and.all in series and that by closing its contacts sici, the relay SICadvances the switch TBV by one step. When the said timing pulse ceases,the relay SIC is deenergized, and this has the eiiect that a relay SL isenergized by wary of thecontact ska, the winding oi the relay SL, thecontact son and the winding of the relay SM, Whereby'the latter relay islocked and the relay SL closes the contact sh.

rihe subsequent timing pulses received by the relay SIC have the effectthat by closing thecon tact sieg, this relay closes an earth connectionto the conductor Do by Way ofthe contacts ssi, szcz and S11 inseries/whereby' a ineteringpulse i is released inthe metering circuit,not shown,

connected to the conductor Dfo. At thesame time, the switch TBVasadvanced by one each time the Contact sicz'is operated. Y

Asmentioned, the apparatus is constructed in such a manner as toterminate a conversa-tional period in the course of three minutes. Thecharge tobe made for such a period depends on the distance and otherspecial circumstances the v'switch TCV and the bank contacts oi theVswitch-TAV are made in such a manner that the setting ofthe switch TAVcaused by themetering pulses received and corresponding to the numberoiE such metering pulses determines the number of pulses transmittedduring a conversational period to the relay STC and again transmitted tothe metering circuit by means of the latter relay. The nature of theseconnections is 'apparent from the drawing and may best beunderstood fromthe following description of the operation of the function of the devicewhen ST receives a certain number, e. g. four metering pulses. Un-

jde: these circumstances,` the relay SIC has to receivevthree pulsesdistributed over the conversational period of three minutes, i. e thesepulses are to occur at a time interval cf'llseconds, and as will beapparent from the following, the meterjvingcircuit will then receive atotal of four metering pulses o'f'which the? two first f`ones,"fasmentioned, are transferred directly in by-pass to the switches at thecommencement of the conversational period.

If', as above assumed, the relay ST receives four metering pulses, theswitch TAV will be set in position 4 in the manner described above. Theiirst two pulses are extended to the metering circuit, as abovementioned, by the operation of the contact sts. When the metering pulsescease, the relay ST is de-energized, and this again causes the relay SOto be de-energized. The contact sol connects the switching magnet TCVKof the switch TCV to the timing pulse source which e. g. transmitspulses every fth second, and the switching magnet advances the switchTCV step by step, viz. one step every fifth second. In the exampleconsidered, a timing pulse is to be transferred to the relay SIC every45th second, i. e. the first time in the moment the switch TCV arrivesat its ninth bank contact.' A circuit is then closed from the timingpulse source T via the bank level TAV-d, the wiper w1, the relaycontacts slc and soi, the wiper tw, and the ninth contact of the banklevel TCV-d, the conductor L1, the fourth contact of the bank levelTAV-c, the wiper w1 thereof, the relay SIC, the current source E andearth, whereby the relay SIC receives a pulse from the timing pulsesource T and operates its contacts which, as previously mentioned, causethe relays SM and SL to be operated. At the same time, the switch TBV isadvanced by one step by the temporary operation of the contact sz'ci ofthe relay SIC.

When the switch TCV has been advanced by another nine steps, i. e. tothe contact i8, the mentioned circuit via the re'ay SIC is closed again,this time by way of the contact I8 of the bank level TCV-LZ instead ofthe contact 9 thereof. Accordingly, the relay SIC receives anothertiming pulse and again closes its contacts 'sz'ci and sicz which has theeffect that a pulse is again released over the contacts ssl, szcz andsli. Besides, the switch TBV is advanced by another step by thetemporary operation of the contact sich The switch TCV is continvallyadvanced by one step every fifth second, and when it passes position 24,a circuit is closed from the timing pulse source T, the bank levelTAV-d, the wiper w1 thereof, the relay contacts scs and soi, the wipertw of level TCV-d, the contact 24 thereof, the relay SY and the currentsource E- whereby the relay SY is energized and locks itself over therelay contacts, a contact 3.1/5 controlled thereby, and the contact ske.At the same time, the relay SY opens another contact syi controlledthereby, whereby a relay SYA, which was operated upon operation of therelay SK is de-energized. During the de-energizing time of the relaySYA, a circuit for the switching magnet TCVK is closed by way of thecontacts sil/4 and sym in series. The switch TCV is accordingly advancedby one step from position 24 to position 25 andl has thereby passedthrough all of its contact positions l-25 which are assumed to beuniformly distributed along a circular arc of 360, this assumption alsoapplying to all of the other switches TAV and TBV. Accordingly, whenunder the continued influence of the timing pulses, the switch TCVcommences a new cycle through its contact positions, then, when 45seconds have passed since it was set on the contact I8, it Will arriveat the contact 3, and the relay SIC then receives another pulse from thetiming pulse source T by way of the bank level TAV-d, the wiper thereof,the contacts slcs and soi, the wiper tw, and the contact 3 of the banklevel TGV-d,

the contact Sys closed by the relay SY, the contact 4 of the bank levelTAV-c and the` wiper w thereof. Thereby a pulse is again transmittedtothe metering circuit, and the latter accordingly has received a totalof four pulses corresponding to the charge for the call in question. Atthe same time, the switch TBV is advanced by another step, viz. to thebank contact 4, it being remembered that this switch was advanced by onestep when the switch TCV was advanced by the iirst step.

Since each of the bank contacts l-24 of the bank level TBV-a isconductively connected with a bank contact in a corresponding positionin the bank level TAV-a, i. e. the bank contact 4 of the bank levelTBV-a is connected with Athe bank contact 4 of the bank level TAV-a, therelay SS will now be energized from the current source E via the relaySS, the wiper w of the bank level TAV-a, the fourth bank contactthereof, the fourth bank contact of the level TBV-a, the wiper wbthereof, the contact sin; and the contact soz to earth. The relay SS isoperated and is held by a contact shi of a relay SH in series with acontact ssi of the relay SS itself, the latter contact at the same timepreventing more pulses from being transmitted to the metering circuit byinterrupting the earth connection to the conductor Dfo. When the relaySS operates its contacts, the relay SK is de-energized. Moreover, ahoming circuit for the switch TAV is closed over the contact ssa of therelay SS, the wiper w of the bank level TAV-e, the self interruptingcontact INT-TAV, the switching magnet TAVK and the current source E. Theswitch TAV is then restored to its home position, i. e. to position 25and thereby closes a homing circuit for` the switching magnet TBVK ofthe switch TBV via the contact ssz, bank contact 25 of level TAV-e, thewiper wb of bank level TBV-b, a contact of this level and the selfinterrupting contact INT-TCV, whereby the switch TBV is likewiserestored to position 25. TherebyI a circuit is closed from earth by wayof the bank contact 25 of level TAV-e, the wiper wb of level TBV-b, thebank contact 25 thereof, the wiper tw of level TCV-e, the selfinterrupting contact AINT-TCV thereof, and the switching magnet TCVKwhich then restores TCV to its home position on the contact 25. Therelay SH is now energized over the contact ssz and the wipers w, wb andtw of the levels TAV-e, TBV-b and "TCV-e in series and opens its contactshi, whereby the relay SS is de-energized and interrupts the circuitconnection over SI-I, which is likewise deenergized.

The described apparatus is then ready to receive a new metering pulseseries.

If the relay ST receives a greater number of pulses, e. g. nine, theswitch TAV is automatically advanced to the ninth contact of its banklevels, and the above described functions are repeated only with thedifference that nine timing pulsesl are now transmitted over theswitches TUV and TAV to the relay SIC with equal time intervals of 20seconds. This means that the relay SIC received such a pulse for eachfour step by which the switch TCV is advanced to be set on the bankcontacts 1i, 8, l2, le, 2G and 24 during the rst travel over all of thebank contacts and when set on the bank contacts 4 and tl during thesecond travel. As appears from the drawing the bank contacts 4, 8, I6and 20 of the bank level TCV-c are directly connected to the 7th, 8thand 9th bank contact of the bank level TAV-c, whereas thebank contactsi2. and 2t of' The relay SX. controls threeV contacts sri, sez

and san. The contact sx1 is arranged to, close the impulse circuit cithe relai7 lSIC, when the wiper of the bank level TAV-c is set on the9th bank contact, whilst the wiper of the bank level TCVwc at the sainetime is set on the 12th or 24th banlr contact. The contact sxz isarranged to close the impulse circuit of the relay SiC when the wipertic of the bank level TGV-c is set on the 6th banlr contact of said banklevel, corresponding to an impulseV interval of 3Q seconds, and thewiper of the bank level TGV-c is set on ne 12th and 241th bank contact.Ii the number oi metering pulses received becomes greater than iii, thetiming pulses advancing the switch TGV must occur shorter time intervalsVthan seoonds, e. g. at etime interval of 2, 5 seconds in order than asufficiently uniform distribution of the many pulses transmitted by therelay SIC should be obtained. With a view to this, the contacts of banklevel TAV-d is split up so that timing pulses are transmitted at aninterval of 5 seconds from the timing pulse source T, if the said switchis in a position between i and lf3 whilev pulses are transmitted at timeinterval of 2 5 seconds from another timing pulse source t if the switchTAV is in a position between lv and 26.

Having now particularly described and ascertained the nature of my'invention and in what manner the saine is to be performed, I declarethat what l claim is l. in a telephone system, the provision of acircuit arrangement for controlling the charge for the duration ot acalling subscribers telephone call, corn ising in combination a sourcefor transmitting metering pulses, a meter respcnsive to said pulsesV atiming circuit interposed between said source o1" pulses and said meterand comprising a member responsive to said pulses, a iirst steppingVswitch controlled by said pulseresponsive niernber to be automaticallystepwise onestep for each pulse received by said responsive member, asecond stepping switch, a timing device connected in the'operatingcircuit ci saidrtwo stepping switches to advance this said second switchstepwise at predetermined time in" tervals, circuit connections betweendiiierent groups of barile contacts cf one level oi saidV sec ondstepping switch and groups of bank contacts of one level of said iirststepping switch to connect the timing device at intervals dependent uponthe number of received metering pulses to the wiper of said level of thefirst stepping switch, a relay `responsive to current pulses produced bysaid timing device in the circuits extended from said device by way ofthe said bank contacts and the said two wipers and arranged to transmitsaid current pulses to the operating circuit or the subscribe1"s meter,a third stepping switch arranged to be set stepwise by the operation ofthe member responsive to the pulses transmitted from the mst-mentioned'source of pulses and' transmit` from the said source of pulses directlyto the subscribers meter,v and to be set further by. the operation ofthe said relay during the transmission or pulses to the subscribersmeter' by the operation of this relay, the bank contacts of one level,of said third stepping switch andy the bank. contacts ci one level ofthe said rst stepping switch being interconnected in pairs to cause, thewiper of said two levels to be electrically interconnnected when thesaid wiper of the third stepping switch is set on a bank contact whichis connected to that bank contact of the last-mentioned level ci thefirst stepping switch on which the wiper ol this level has been set bythe operation of the member responsive to the metering pulse, in orderto complete a current circuit through said wipers for interrupting thecall automatically.

Y 2. In a Atelephone system according to claim 1 means for preventingthe first one of the current pulses transmitted from the timing deviceto the relay connected in the'circuit of the wipers of the nrst andsecond stepping switches to be transferred to the operating circuit ofrthe calling subscribers meter.

3. In a telephone system, the provision of a circuit arrangement forcontrolling the charge for the durationof a calling subscriberstelephonecalls, comprising in combination a source for transmitting meteringpulses, a meter responsive to said pulses, a pulse responsive memberreceiving said pulses, a stepping switch operable one step by each ofsaid. metering pulsesY received by said pulse responsive member,circuit, connections between said meter and said stepping switch andbetween said stepping switch and said pulse responsive member fortransmitting some of said metering pulses at the commencement of a calldirectly to the said meter, means for interruptingV the transmission tosaid meter of Vfurther rnetering pulses received by said pulseresponsivel member, a timing device forv producing timing pulsesy tosubstitute said further metering pulse, and means responsive to saidtiming pulses and controlling contacts connected in the circuit of saidmeter to transmit said timing pulses to said meter at time intervalsbetween each two con secutive timingpulses which are larger` than theintervals between consecutive metering pulses received by the said pulseresponsive member, and means for determining the said longerinterval oftime automatically in dependency on the nuni ber oi pulses received bythe said pulse responsive inernber.

ERNEST UNGAR;

REFERENCES. CTED The following references are of record in the nle ofthis patent:

Number Name Date` 1,726,983 Friendly Sept; 3, 192 1,853,077 PetersonvApr. 12,1932 2,094,060' Busch Sept. 28, les?

